Anss/nsmp Strong-motion Record Processing and Procedures

The USGS National Strong Motion Program (NSMP), in cooperation with 17 partners, currently operates a permanent network of more than 675 digital and 265 analog strong motion instruments. These recorders, each with 3 to 18 channels of data, are located at 673 sites, including ground motion reference sites and structural arrays, distributed throughout 32 states and Puerto Rico. About half of these sites are in California. More than 320 of the digital instruments have continuous or dialup telecommunications. Earthquake records obtained from these instruments are collected in Menlo Park for archiving, processing and dissemination. Data obtained in near-real time are automatically processed for preliminary estimates of parametric values (e.g., peak ground motions) that are fed to other applications, such as ShakeMap, and for posting to websites such as the CISN Engineering Data Center (http://www.cisn-edc.org), but all of the records are reviewed and re-processed before final release. This paper summarizes the routine, record processing procedures currently practiced by NSMP.